make no sense

[Chris17]

so this is what i don't understand why my car starts fine during the day but in the eveing or morning that car doesn't start like its not gettin gas... could the fuel pump be gettin affected by the moisture at thoes times???

its a 94 9c1

[CD Smalley]

I'd guess the fuel pump relay and it's connector, what's that thing called that would melt underhood there? A stud of somekind....

That could be doing it.

Does the car crank and not fire at these times?

In your case it could also be the opti-crap going south.

[Chris17]

the car turns over and everything just doesn't fire... the opti and coil are both new i originally thought that was the prob so i know it's not that... the stud by the underhood fuse box seems fine (doesn't look melted or anything like that)... when it starts it runs perfectly fine. that why im lost it's like it knows what time it is and jus dont start

[j cAT]

Originally Posted by Chris17

the car turns over and everything just doesn't fire... the opti and coil are both new i originally thought that was the prob so i know it's not that... the stud by the underhood fuse box seems fine (doesn't look melted or anything like that)... when it starts it runs perfectly fine. that why im lost it's like it knows what time it is and jus dont start

when the engine won't start disconnect MAF electrical connector if it then starts it's most likely the maf temperature section thats bad......

[Chris17]

tonight i went and disconnected the maf sensor and the same thing nostart. i notice that the fuel pump doesn't kick on when i turn the key... so i changed the fuel pump and relay still the same thing. starts during the day and not at night i have no idea whats wrong and im bout to give up on this car

[j cAT]

Originally Posted by Chris17

tonight i went and disconnected the maf sensor and the same thing nostart. i notice that the fuel pump doesn't kick on when i turn the key... so i changed the fuel pump and relay still the same thing. starts during the day and not at night i have no idea whats wrong and im bout to give up on this car

so now we know when its dark out the fuel pump don't run and you replaced the fuel pump and relay and still no fuel pump! you must get voltmeter and check when fuel pump fails to run, also check all connectors to fuel pump/relay/fuses with meter, eyes are not good for this.just a thought , at night when key to ignition but starter not engaged do headlights come on because its dark out. if so stop this , and see if car starts. if still cant find loss of power to pump i will give you pcm connections wires to check as pcm controls fuel pump relay.....

[Chris17]

so i get power t0 the relay and the pump and still no start... what pcm wires should i check next?

[j cAT]

Originally Posted by Chris17

so i get power t0 the relay and the pump and still no start... what pcm wires should i check next?

measure at the fuel pump connector next to gas tank do not use frame of car for ground i believe it must be bad ground wire near tank.the gray wire is fuel pump 12v. the black wire is ground, pump must run if 12v across these wires to pump. if pump does not run then pump or wires in tank to pump n/g , . you did say fuel pump does not run, and you just replaced it right? and you have 12v at pump? measure at fuel tank black wire that is from car body not pump/gas tank. black wire resistance to frame ground should be zero ohms .......if this wire is not zero ohms then follow wire back to where it is connected to frame, remove screw clean rust reconnect and measure again.this should be on drivers side in trunk area. you must use a dc volt/ohm meter. other devices to measure are not going to help in finding this problem

[Blue Bowtie]

If you're getting at least 11.8V to the fuel pump (KOEO) for the two-second prime cycle when the ignition is turned on, you might want to test the fuel pressure. Expect to read at least 43 PSIG, ± 3 PSIG with the engine off.

At this point, there's really no reason to suspect any problems with the PCM, so don't even bother opening that can of worms.

[Chris17]

it seems like im gettin power to everythin i need to get power to... still don't understand why it wont start at night... i think im just goin to bring it to a mechanic...

thanks for all the help, ill let u know what it ended up being when i find out what it is

[Chris17]

FINALY GAVE UP!!! brought the car to a mechanic and they coulnd't figure it out... so i ended up fixin the transmission on my 78 pontiac catlina.

thanks for all ur help wont be comin back to the threads as i have givin up


any1 want to buy a 94 9c1 that doesn't start at night???

[j cAT]

Originally Posted by Chris17

FINALY GAVE UP!!! brought the car to a mechanic and they coulnd't figure it out... so i ended up fixin the transmission on my 78 pontiac catlina.

thanks for all ur help wont be comin back to the threads as i have givin up


any1 want to buy a 94 9c1 that doesn't start at night???

its hard to help you when you don't give specific details when you say everything checks out but the engine don't start at night. need voltage measurements to determine where power to fuel pump is lost when the sun goes down.....also get a different auto tech mechanic ....